JP2002211469A - Body structure for motorcycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply form a journaling structure for a rear swing arm front end part with a beautiful appearance when a diamond frame style is employed and to flexibly structure a body. SOLUTION: A pivot part 20 is integrated with the respective lower ends of a center frame 13 and a rear frame 14 vertically disposed on the rear side of a crank case 16 for an engine, and then the connection part of a rear swing arm 21 is swingingly journaled to a pivot shaft. A bracket 22 used as a hanger at the same time is coaxially mounted with the pivot shaft between the pivot part 20 and the connection part, an engine hanger is formed by projecting a part thereof frontward, and a stay formed at the rear stump of the crank case 16 is connected and supported there. A stay 53, a step 56 and the like are mounted to the bracket 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle body structure of a motorcycle, and more particularly, to a motorcycle having a simplified structure for supporting a rear swing arm and having a flexible body.

[0002]

2. Description of the Related Art Japanese Patent No. 2646487 discloses that an engine is formed as a part of a vehicle body frame, and a block-shaped bracket is fastened to a rear portion thereof by attaching the bracket to the front and rear sides of the rear swing arm at the left and right sides of the bracket. FIG. 1 shows a vehicle body structure of a motorcycle in which is pivotably supported. In addition, a pair of left and right pivot plates are attached to a center frame behind the engine with a long welding line, and a rear swing arm is pivotally supported between the two pivot plates.

[0003]

However, in the case where the vehicle body is freely adjustable as in the above-mentioned conventional example, the support structure of the rear swing arm is complicated and it is difficult to improve the appearance. In addition, where the body tends to be flexible recently,
In such a vehicle body configuration, since the rear swing arm is firmly supported by the engine, it is difficult to form suppleness. In addition, when the pivot plate is welded to the center frame, a long weld bead is exposed, so that advanced design processing is required to improve the appearance. Then, this invention aims at realization of such various requests.

[0004]

In order to solve the above-mentioned problems, a motorcycle body structure according to the present invention comprises a main frame disposed above and below the engine in a front-rear direction, and a rear portion of the main frame. A motorcycle having a center frame extending downward at the rear and connecting the center frame to the engine so that the engine is a part of the body frame. An extension portion is provided, a pivot support portion is provided at a lower end portion of each of these extension portions, and a front end portion of a rear swing arm constituting a rear wheel suspension is inserted between these left and right pivot support portions, and each shaft is connected via a pivot shaft. A hanger double bracket that is swingably supported by the support and coaxially supported by the pivot shaft between the shaft support and the rear swing arm. The provided bets, characterized in that it supports the lower rear portion of the engine at the hanger combined bracket. At this time, the center frame is formed in a pipe shape,
The shaft support may have a boss shape.

[0005]

According to the present invention, by connecting the center frame to the engine, the engine can be used as a part of the body frame, and a pair of left and right shaft support portions are provided below the engine connection portion of the center frame.
Since the rear swing arm is swingably supported by the hanger and bracket between the shaft supports, there is no need to provide a strong and large bracket to the engine as in the conventional example described above. It can be simple and look good.

[0006] In addition, a hanger bracket is coaxially supported by a pivot shaft between the shaft support portion and the rear swing arm, and a part of the hanger bracket is supported below the rear portion of the engine. The body frame can be made more flexible than the body structure described above.

In addition, since the hanger bracket is formed as a separate member from the extending portion, the center frame is formed in a pipe shape.
The pivot portion can be a boss-shaped member formed at the lower end thereof, so that there is no need to provide a pivot plate by welding to a pipe-shaped center frame as in the related art, and the weld bead is not greatly exposed, Appearance can be improved. In addition, if the step is mounted on the hanger bracket, the step mounting part does not have to be directly welded to the body frame, so the mounting position accuracy of the peripheral parts will not be disrupted by the thermal distortion of welding, and accurate mounting is possible. Become.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. First, the overall structure of a motorcycle to which the present invention is applied will be outlined. FIG. 1 is a left side view of the motorcycle, and FIG. 2 is a right side view thereof. As is apparent from these figures, the front fork 2 supporting the front wheel 1 is supported at its upper part on the front part 6 of the body frame 5 via the bottom bridge 3 and the top bridge 4 and is rotatable by the handle 7. I am. A headlight 8 is attached to a front portion of the vehicle body frame 5, and front blinkers 9 are attached to both left and right sides thereof.

The body frame 5 has a front portion 6 formed by forging or the like, a single main frame 10 extending substantially horizontally rearward along the center of the vehicle body, and a rear portion extending obliquely downward and rearward from the front portion 6. A down frame 11, a pair of left and right seat rails 12 extending substantially horizontally rearward from the rear of the main frame 10, and a pair of left and right center frames 13 extending diagonally downward and rearward from the rear of the main frame 10; By connecting the lower end of the center frame 13 and the rear end of the seat rail 12 diagonally,
And a pair of left and right rear frames 14 forming a substantially V-shaped space in side view between them. Each of these frame members is a pipe made of an appropriate metal such as iron or aluminum alloy, and is a round pipe on the present embodiment side.

The lower part of the down frame 11 is empty (or oil).
It is connected to a front part of a crankcase 16 in a cold in-line four-cylinder four-cycle engine 15. The upper rear portion of the crankcase 16 is connected to the center frame 13 by an engine hanger 19 which extends obliquely downward and forward from an intermediate portion of the center frame 13, so that the vehicle body frame 5 allows the engine 15 to be a part of components. It has become a diamond frame.

The lower ends of the center frame 13 and the rear frame 14 are connected to each other by a boss-shaped pivot portion 20, and a pivot shaft (not shown in FIG. 5, see FIG. 5) at the left and right pivot portions 20. ), The front end of the rear swing arm 21 is rotatably supported, and a hanger / bracket 22 described later supported on a pivot shaft.
, The lower rear portion of the crankcase 16 is supported.

At the rear end of the rear swing arm 21, a rear wheel 23 is rotatably supported.
4 is driven by a chain 26 wound between a drive sprocket (not shown) housed inside a sprocket cover 25 provided at the rear of the crankcase 16. A rear cushion unit 27 is provided between the rear portion of the rear swing arm 21 and the rear portion of the seat rail 12, and constitutes a rear wheel suspension.

The fuel tank 2 is provided on the main frame 10.
8 supported and seated rearward and adjacent thereto
9 is supported on the seat rail 12. Rear end 29a
Constitutes a backrest portion 29 integrally projecting obliquely upward. Although the sheet 29 is a single sheet in this embodiment, it can be arbitrarily replaced with a double sheet.

A tail cowl 30 having a substantially triangular shape in side view is provided in contact with the back surface of the backrest 29a. The tail cowl 30 is a member made of an appropriate material such as resin.
The front slope 31 side in contact with the backrest 29a is the widest portion in the vertical direction, and extends from here toward the rear in a tapered shape, and the rear end 32 has an acute angle.

A tail unit 33 is mounted near the rear end 32. The tail unit 33 has a license plate 35 attached to each rear end of a pair of left and right sheet metal frames 34, and further has left and right rear blinkers 36 attached to the side surfaces of the sheet metal frame 34, and is integrated with a license lamp and the like not shown in the figure. is there.

Reference numeral 40 in the drawing denotes a front brake hose, which is provided in a pair of left and right sides, between a master cylinder (not shown) of a handle lever and a brake caliper 41 of a dual brake provided in a pair on the left and right sides of the front wheel 1. It is connected. The brake caliper 41 is supported below the front fork 2 via a caliper bracket 42,
It comes into sliding contact with a pair of left and right brake discs 43.

Reference numeral 44 is an oil cooler, and 45 is an air cleaner. The air cleaner 45 includes an electronic injection unit 46.
The air-fuel mixture is supplied to the cylinder head 17 from the electronic injection unit 46 by connecting to the intake port of the cylinder head 17 of the engine 15 via the. Reference numeral 47 denotes a cover of the air cleaner case, which is disposed in a substantially triangular space surrounded by the seat rail 12, the center frame 13, and the rear frame 14. As shown in FIG. 2, a battery 48 and a fuse box 49 are accommodated in the substantially triangular space on the right side of the vehicle body.

The exhaust gas is guided from an exhaust port of the cylinder head 17 to a muffler 51 at the rear of the vehicle body via an exhaust pipe 50.
The exhaust pipes 50 are separated into two at the left and right sides of the vehicle body and assembled, and further connected to a pair of mufflers 51 disposed at the left and right sides of the vehicle body.

Reference numerals 52 and 53 denote pipe-shaped stays for supporting the muffler 51, of which upper stays 52 are provided.
Extends rearward from an intermediate portion of the rear frame 14, and the lower stay 53 extends rearward from the rear end of the hanger / bracket 22 and has a substantially triangular shape in side view.

The hanger and bracket 22 provided on the left side of the vehicle body shown in FIG.
Side stands 55 are rotatably supported at the center side, and a step 56 is mounted behind the side stand 55. 2, the lower part of the front of the hanger bracket 22 projects forward to form an engine hanger 57, which supports the lower part of the crankcase 16.

The hanger / bracket 22 on the right side of the vehicle body shown in FIG. 2 has the same structure as that on the left side of the vehicle body.
8 are provided.

Next, the support structure of the rear swing arm 21 and the support structure for the rear lower part of the engine 15 will be described. FIG. 3 is an enlarged left side view of a main part of the vehicle body, FIG. 4 is a view further illustrating the pivot portion 20 and the hanger / bracket 22 on the right side of the vehicle body, and FIG. 5 is a sectional view taken along line 5-5 in FIG.

As is apparent from FIGS. 3 and 4, the hanger / bracket 22 on the right side of the vehicle body is formed separately from the pivot portion 20 by press forming, casting or forging a metal as appropriate, and the outer portion formed on the lower side thereof is formed. Step 6 protruding toward
At 0, a boss 61 formed at the tip of the stay 53 is bolted, and a step 56 is attached below the boss 61. Although not apparent in the figure, step 56 is
It is rotatably supported by being pivotally mounted on a shaft support formed integrally therewith.

A brake pedal 58 is rotatably supported on a shaft support 62 at a front portion of the step portion 60, and a master cylinder 64 of a rear brake is provided near a shaft attachment portion via a link 63.
It is connected to. Further, an engine hanger 57 projecting forward is formed at a lower front portion of the hanger / combination bracket 22 and is connected to a stay 66 formed at a lower rear portion of the crankcase 16. A bush 67 is provided on the stay 66, and a bolt 65 is provided. , Nut hanger 5 with engine hanger 5
7 (FIG. 5). This allows the engine 15
The lower back is supported. The structure of the hanger / bracket 22 is the same also on the left side of the vehicle body.

As shown in FIG. 5, the pivot portion 20 has a circular boss shape in a side view which is welded and integrated together with the lower ends of the center frame 13 and the rear frame 14, and is provided on one end of a pivot shaft 70 on the outside. The formed head 71 contacts. The pivot shaft 70 has a long bolt shape, and a through hole 72 provided in the pivot portion 20 and a through hole 73 provided in the center of the hanger / bracket 22 are aligned with each other.
These are passed through a collar 74.

The pivot shaft 70 is passed through a bearing 76 in a connecting portion 75 integrally formed on the right and left sides of the front end of the rear swing arm 21, and a nut is fastened to a screw portion (not shown) on the distal end side passing through the connecting portion 75. Integrated.

Next, the operation of this embodiment will be described. FIG.
As is clear from FIG. 5, the pivot portion 20 is connected to the rear frame 1.
4 is extremely small and has the same diameter as that of the center frame 4 and is integrally welded to the lower ends of the center frame 13 and the rear frame 14. Therefore, the weld bead is exposed to the minimum necessary, and there is no unnatural feeling in appearance, and the center frame 13 and the rear frame 14 are formed in a round pipe shape so as not to impair delicate design processing.

In addition, the pivot portion 20 for pivotally supporting the rear swing arm 21 can be simply configured, and the appearance can be improved.

Further, a hanger / bracket 22 separate from the pivot portion 20 is provided, and this is inserted between the pivot portion 20 and the connecting portion 75 of the rear swing arm 21.
In addition, the lower part of the crankcase 16 is supported as the engine hanger 57 by using a part of the hanger / combination bracket 22 as the engine hanger 57. Therefore, a diamond frame type in which the engine 15 is a part of the body frame is adopted. Nevertheless, unlike the prior art, the rear swing arm is not directly attached to the engine 15 and the hanger / bracket 22 is fastened and fixed between the pivot portion 20 and the connecting portion 75 of the rear swing arm 21. Unlike the method in which the plate is welded to the frame, the vehicle body can be given flexibility and the adjustment of the rigidity of the frame is facilitated.

Further, the right hanger / bracket 22 is also used.
The stay 53, the step 56, the collar 74 and the left hanger / bracket 22
Since the gear shift pedal 54 can be attached, attachment of these peripheral members becomes easy. In particular, step 56
Is not directly attached to the vehicle body frame by welding as in the prior art, so that the mounting accuracy is not disturbed due to thermal distortion, and the peripheral members can be mounted at accurate positions.

[Brief description of the drawings]

FIG. 1 is a left side view of a motorcycle to which the present invention is applied.

FIG. 2 is a right side view of the same.

FIG. 3 is an enlarged left side view of a main part of the vehicle body.

FIG. 4 is an enlarged view showing a portion around a pivot portion on the right side of the vehicle body;

FIG. 5 is a sectional view taken along line 5-5 of FIG. 4;

[Explanation of symbols]

Body frame 5, Main frame 10, Down frame 11, Seat rail 12, Center frame 13, Rear frame 14, Engine 15, Crank case 16, Engine hanger 19, Pivot part 20, Rear swing arm 21, Hanger / bracket 22, Gear shift Pedal 54, side stand 55, step 56, engine hanger 57, stay 66, pivot shaft 70, connecting portion 75

Claims (2)

[Claims] 1. A main frame disposed in the front-rear direction above an engine, and a center frame extending downward from the rear of the main frame to the rear of the engine. The center frame is connected to the engine to connect the engine to a body frame. And a pair of left and right extending portions extending downward from the engine connecting portion on the center frame, and a shaft supporting portion provided at a lower end portion of each of the extending portions. Insert the front end of the rear swing arm that constitutes the rear wheel suspension between the shaft supports, and swingably support each of the shaft supports via the pivot shaft, and coaxially between the shaft support and the rear swing arm by the pivot shaft. A hanger-supporting bracket supported by the hanger is provided, and this hanger-supporting bracket supports the rear lower part of the engine. The body structure of a motorcycle that is a feature. 2. The motorcycle body structure according to claim 1, wherein the center frame has a pipe shape, and the shaft support has a boss shape.